Patch "octeontx2-af: cn10k: Do not enable RPM loopback for LPC interfaces" has been added to the 5.16-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    octeontx2-af: cn10k: Do not enable RPM loopback for LPC interfaces

to the 5.16-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     octeontx2-af-cn10k-do-not-enable-rpm-loopback-for-lp.patch
and it can be found in the queue-5.16 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b6eba955a5e4e540717e64a81fb66d55e1fd5530
Author: Geetha sowjanya <gakula@xxxxxxxxxxx>
Date:   Fri Jan 21 12:04:45 2022 +0530

    octeontx2-af: cn10k: Do not enable RPM loopback for LPC interfaces
    
    [ Upstream commit df66b6ebc5dcf7253e35a640b9ec4add54195c25 ]
    
    Internal looback is not supported to low rate LPCS interface like
    SGMII/QSGMII. Hence don't allow to enable for such interfaces.
    
    Fixes: 3ad3f8f93c81 ("octeontx2-af: cn10k: MAC internal loopback support")
    Signed-off-by: Geetha sowjanya <gakula@xxxxxxxxxxx>
    Signed-off-by: Subbaraya Sundeep <sbhatta@xxxxxxxxxxx>
    Signed-off-by: Sunil Goutham <sgoutham@xxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rpm.c b/drivers/net/ethernet/marvell/octeontx2/af/rpm.c
index 4cbd91540f999..9ea2f6ac38ec1 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/rpm.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rpm.c
@@ -291,23 +291,20 @@ int rpm_lmac_internal_loopback(void *rpmd, int lmac_id, bool enable)
 	if (!rpm || lmac_id >= rpm->lmac_count)
 		return -ENODEV;
 	lmac_type = rpm->mac_ops->get_lmac_type(rpm, lmac_id);
-	if (lmac_type == LMAC_MODE_100G_R) {
-		cfg = rpm_read(rpm, lmac_id, RPMX_MTI_PCS100X_CONTROL1);
-
-		if (enable)
-			cfg |= RPMX_MTI_PCS_LBK;
-		else
-			cfg &= ~RPMX_MTI_PCS_LBK;
-		rpm_write(rpm, lmac_id, RPMX_MTI_PCS100X_CONTROL1, cfg);
-	} else {
-		cfg = rpm_read(rpm, lmac_id, RPMX_MTI_LPCSX_CONTROL1);
-		if (enable)
-			cfg |= RPMX_MTI_PCS_LBK;
-		else
-			cfg &= ~RPMX_MTI_PCS_LBK;
-		rpm_write(rpm, lmac_id, RPMX_MTI_LPCSX_CONTROL1, cfg);
+
+	if (lmac_type == LMAC_MODE_QSGMII || lmac_type == LMAC_MODE_SGMII) {
+		dev_err(&rpm->pdev->dev, "loopback not supported for LPC mode\n");
+		return 0;
 	}
 
+	cfg = rpm_read(rpm, lmac_id, RPMX_MTI_PCS100X_CONTROL1);
+
+	if (enable)
+		cfg |= RPMX_MTI_PCS_LBK;
+	else
+		cfg &= ~RPMX_MTI_PCS_LBK;
+	rpm_write(rpm, lmac_id, RPMX_MTI_PCS100X_CONTROL1, cfg);
+
 	return 0;
 }